Science Alert | In the first part, I mentioned how some appliances use a considerable amount of energy when not in use. For example, my son recently installed a 5-star split-system air-conditioner. It draws 10 watts on standby.
If we do the calculations, 10 W (watts) for 24 hours a day, 365 days a year comes to 88 kWh (kilowatt hours) per year.
Now let’s work out its likely usage when operating. Say we have 20 hot days a year when the system is running flat out for 8 hours. Let’s conservatively assume that running flat out, it draws 550 watts. The sum of 550 watts for 8 hours for 20 days comes to 88 kWh per year.
This 5-star-rated appliance uses as much energy on standby as doing its job. Systems like this should be installed with a switch so they can be turned off completely for most of the year.
One last point. I have only considered domestic hot water, lighting, cooking and domestic appliances. I have not mentioned space heating, transport, holidays, the workplace and the energy in all the goods and services we buy.
That comes in the next exciting episode!
If we do the calculations, 10 W (watts) for 24 hours a day, 365 days a year comes to 88 kWh (kilowatt hours) per year.
Now let’s work out its likely usage when operating. Say we have 20 hot days a year when the system is running flat out for 8 hours. Let’s conservatively assume that running flat out, it draws 550 watts. The sum of 550 watts for 8 hours for 20 days comes to 88 kWh per year.
This 5-star-rated appliance uses as much energy on standby as doing its job. Systems like this should be installed with a switch so they can be turned off completely for most of the year.
One last point. I have only considered domestic hot water, lighting, cooking and domestic appliances. I have not mentioned space heating, transport, holidays, the workplace and the energy in all the goods and services we buy.
That comes in the next exciting episode!
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